Spark-plugs



F. o. HSK. I METHOD 0F MANUFACTURINIGISPARK PLUGS.

vAPPLICATION FILED-JUNE 20. 1919;

1,333,400. Pawntd' Mr. 9, 1920.

i when in the molten state.

FREDERICK c. rrsK, or WILLIAMsvrLEnmEWYour: s

MTI-IOD 0F MANUFACTURING SPARK-PLUGS.

Specification of Letters Patenti Patented Mar.y 9, 1920.

Application led .Tune 20, 1919. Serial No. 305,681.

lo all 'Lc/1.0m it may conce/rn.'

Be it known that I, FREDERICK C. FISK, a citizen of the United-States ofAmerica, residing in the town of 1Williamsville, county of Erie, andState of New York, have invented certain `new and useful Improvements inMethods of Manufacturing Spark- Plugs, of which the following is a full,clear,

and exact description.

My invention relates generally to a method of manufacturing spark plugs,and more particularly to that type of spark plug in which an auxiliaryspark gap is provided.

In making spark plugs of this type, glass is usually used as theinsulating material because of its transparency and fluidity Theauxiliary spark gap is usually formed at some distance from the exposedends of the electrodes of the spark plug and difficulty isexperienced-in properly supportingthe electrodes, 'so that they willremain in the proper alinement when the glass is poured within thematrix and around them. It is also difficult to prevent the molten glassfrom flowing in between'the auxiliary spark gap in the ordinary methodof manufacturing such plugs.

The general object of my invention has been to-provide a method in whichthe insulators for suc-h plugs may quickly made, and in which the innerends of the electrodes, in the auxiliary spark gap, shall be positivelvheld in alinement and in predetermined relation with each other.

In the accompanying drawings, forming part of this application, I haveshown one part of an apparatus for carrying out my method; and, it isclear, that any other suitable molding apparatus may be used.y

In the drawings:

Figure 1 represents the face view of one part of the molding flaskshowing the electrodes in position.

Fig. 2 shown a fragmentary portion of the same part, with the insulatormolded and in section.

In the drawings 5 represents one portion' of the customary t\vo'partmolding flask, which is, of course, provided with the pouring opening,not shown. 6 is the matrix of the'flask which is of a shape to provideany desired form of insulator, the form shown being 'one in which ataper is provided at be easily and each end of the insulator with anannular flange near the middle portion thereof.

7 and 8 are annular supporting disks which are centrally arranged withinrecesses 9 and 10, respectively. These recesses are formed within theparts of the flask, and preferablyk a slight distance from the ends ofthe matrix 6, with walls 11 therebetween. Each of the disks is providedwith ay central aperture 12 and a set screw 13, whereby the exposed endsof the electrodes 14 and 15 may be suitably clasped and held. The innerends of each of the electrodes is preferably provided with aperipherally reduced portion 16, whereby a vshoulder 17 isformed oneach. 18 is a perforated, hollow,` Aglass sphere or a perforated bead,in the op ositely arranged openings of which are posed the portions 16of the electrodes. The shoulders 17 are so positioned as toprovide apredetermined spark gap between the ends of the electrodes when theshoulders are pressed in contact with the outer surface of the head. Theelectrodes are, ofcourse, held in this predetermined position by thedisks 7 and 8. l

When my process is carried out by the apparatus herein shown anddescribed, the parts of the fiask and the. electrodes are, of course,first heated. The portion 16 of the electrodes are'placed in positionwithin the bead 18 and the outer ends of the electrodes are then placedin position and firmly secured within the disks 7 and 8. The disks arethen placed within the recesses 9 and 10 and the fiask closed. Themolten glass is now poured within the matrix and surrounds the Thetemperature of the molten glass will be sufficient to fuse with theglass bead 18 and make the same an integral part of the insulator. Afterthe flask has become suffilcientlyy cooled it may be opened and the in-`sulator easily and quickly removed therefrom.

Having thus i described my invention what I claim is: i

1 'A method of manufacturing spark plugs which consists in placing theinner ends of the electrodes in the perforations of a transparent sphereand leaving between the ends a space for' the spark gap, then placingthe electrodes and the sphere within thematri'x of the .flasK, and thenpouring molten insulating material Within the matrix and around theelectrodes and sphere.

2. A method of manufacturing spark 5 plugs, which consists lin placingthe inner ends of the electrodes inthe perforations of t'. transparentsphere and leaving between the ends a-space for the spark gap,'then rig#idly supporting the opposite ends of the electrodes within the matrix,and then p0r- 10 ing molten insulating. material -Within the FREDERICKo. Fien;

